4, 4&#39;-alkylidenebis (5-acenaphthenols)



States I 'Ihis"-inventionrelates.to compositions-ofimatter comipri'singenorma'llyhoxidizable organic material stabilizedagz`1inst-fthe'deleteriousJ eiects of oxidationtwith-new and improvedantioxidants. I=The invention is particularly conzcerne'd `rwi'th thestabilization ofsuch-materials as-fats, fattyloils, hydrocarbons,petroleum derivatives, polymeric nmaterials,.-.x/itamirrs,essentialoils, grease-citrus oils, and esirnilaroxidizable organic compositionsemploying 4,4- :alkylidenebis (5-acenaphthenols) as antioxidants. ThisVinvention also Vrelates-toathese compoundsV as new com-Npositions;of'tt1atter.and to means for-,their preparation.

For many years, attempts have Ybeen made to overcome the deleteriouseiects ofoxidation on organic materials which-normally; possessrelatively lowV resistance to oxidation. A1 large number of antioxidantshave been proposedand'are widely usedin stabilizing vthe various`oxidizable4 materials. Because of the widespread use of compositionslwhich need to be stabilized, the search for even more potent andgenerally advantageous,antioxidants iscontinuing.

It is accordinglyan. object of this. invention to=proyide compositionscomprised predominantlyof normallyoxi- Qdizablet organic materialsstabilized with an .improved antioxidant eective topreventgtltedeleterious4 eifects'-iof oxidation for muchlonger-periodsof ytime and Yin afgen-v ferally more advantageous manner thar 1. waspossiblewith gthe antioxidants known heretofore Lkand `.which can beused@in much smaller amounts .theahes'been pessible-wthenyentionahantioxidants- Another object4 of the invention isto stabilize suchmorrn'allypiidizable organic materials as the fattymaterials, ,including vboth solidfats and fatty oils, oxidizablehydrocarbons,'in clud ing the polymeric hydrocarbons, terpenes, e tc.,,petroleum derivatives such as WaXeS, mineral oils,ggasgline-timpregnating foils, fuel oils, and .the like,vitarnins.essentialoils such as., citrus oils, and the like, andsimilanwellknown Ymaterials normally. subjectfto oxidation.

JL-stll further'object of theinvention is .to vstabilize Lnormallyoxidizable organic materials by means of 4,4- alkylidenebis(S-acenaphthenols) whereby improved stat,bilityis Obtained over thevstability resulting from the use of the. conventional antioxidantsknown heretofore.

A further objectofthis invention is to provide 4,4-alkylidene(Sraeenaphthenols) as new compositions of matter-and meansfortheir preparation.

Qther objects will be'apparent from the` descriptionand Claimswhichvfollow.

QInaCCQrdance -with a principal embodiment of. this yinvention there isprovided a newc'lass` of chemical ,compoundshaying the followingformula:

thefelloyynasenerel pas are,wellllnownfinthegart, .f-zinefphlqride, Ininerel, ac ids v Snell .Sulfur .other ,materials such as t ,tive

2,819,974 *Patented Jan. 14, ,135,8

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,andjR' can representrfor, example, a hydrogen atom', an

ethylradicaLan isopropyl radical, acycloalkyl vradical ,suchpas acyclohexylfrvadical, a tertiary,butylfradialma 1), 4,2122eet1y1hexy1idene-bis 5 aaahhellm l Y i 'Y In eeeersineeyvith anotherembodiment 0f fhi S, i11- yention there r`is` provided 'a proeessy forpreparing l these compounds as' inv the above 4general formula whichIcomprises condensing.mathepresence of an :acidic condensing agent5-acenaphthenol1withacarbonyl compound having 1e=RRC,= O whereinlendlbeve. v en. conditions .for v the .employment C above formula .arefairly mil nd `lake,.Melee et.remanentes of from about ,roem temp' a-`.tureertleseup .t0 .earry outythereactian ,at tempereturesef ebeut 2,0

C- The. .reaefia @tiene fer. the. .emnleyrnenttefls-etoriesererfmueh-mer iseteueead tlyelye' the entleymennoffele atefd r,matemperataree and the., strenger acidic condensing agentsf H Y i The-vgeneral Atechniques employed for-the1 .prep eration of the compoundsofithislinventionlare based upon those r etone p,

intheliterature.

Iheacidic eenden figg., agen,tsw

other,knownA n s for A thetgenerel class of, reaetlonspi whieh thiYi,The. f eactieit can. beeenriedputin yerieus. inert. media ethersf,aliplhatia hydrocarbons. ,aromatic hydeearb een 5,:aeenaphthen01end anyofthe aldehydesefgthe genera formule iyenley oyetekeplae reedilytet20,-30 C. Semeofgheeemn beminnen-be ab.t, nedinge9d.yieldf by be...119911 ,he condensation reactiomatmfrorfllo 4 hoursgatfabopt 30 C.Reaction temperatures lower than abo`uti20"v C. can be employed butgenerally otfer no advantages over theraboveirange. The'temperatures offrom 30m-100 Gere permissible buwndeneueh eenditiens theaditien ofther;` Inyl conlpfonndv must `be,carefullyv controlled `so as. toIminimize the1 production ,ofA byproducts.

The S-acenaphthenol employed as a starting material in the reaction canbe prepared according to the method described by ,Ht Rapoport inV the ,Journal of; the American Chemical Society 73,127,19, (1951).

This invention can be further illustrated by the fol lowg ing examplesofi preferred embodiments although Aifwill be understood-that theseexamples are included merely for purposes of illustration and are notintended 4to limit 17 g. (0.1 mole) of S-acenapthenol, 30 ml. of ethylether, 3 g. of calcium chloride, 1 ml. concentrated hydrochloric acid,and 3 drops of thioglycolic acid were mixed in a Z50-ml., 3-neck liask.To the stirred mixture, 4 g. (0.05 mole) of 38% aqueous formaldehyde wasadded dropwise at such a rate to keep the reaction temperature below 30C. After the aldehyde had been added, the mixture was stirred for 15hours at room temperature and was then ref'luxed for 4 hours. The solidwas filtered and washed with water until the wash was substantiallyneutral. The cake on drying weighed 17.5 g. and melted at 21S-220 C.This product was very light colored and without further purification wassuitable for most purposes for use as a stabilizer. Recrystallizationfrom acetone gave a White solid which melted at 224-226 C.

Example 2.-Preparatz'0n of 4,4'-(2-ethylhexyldene)bis (5-acenaphthenol)The reaction conditions disclosed in Example 1 were followed to propare4,4'(2ethylhexylidene)bis(5ace naphthenol) from 8.5 g. (0.5 mole) of5-acenaphthenol and 3,2 g. (0.025 mole) of 2-ethylhexaldehyde. Theproduct was soluble in ether and hence was recovered from the etherfiltrate rather than from the cake as in Example 1. On evaporation ofthe ether, 9 g. of the desired bisacenaphthenol was obtained.Recrystallization from ethanol-water or from 1,2-dichloroethanehexanemixtures gave a product melting at 202-203 C.

Example 3.-Preparation of 4,4'sobutylidenebs (5-acenaphthen0l) Thiscompound was prepared from 5-acenaphthenol and isobutyraldehyde by aprocedure similar to that described in Example l except that benzene wasadded after the ether suspension had been stirred for 15 hours at roomtemperature. The mixture was then heated and the ether was distilled.After the ether was removed, the mixture was refiuxed 2 hours. Theproduct was filtered and washed with water until neutral. g. of lightcolored solid was obtained from 17 g. (0.1 mole) of 5-acenaphthenol and3.6 g. (0.05 mole) of isobutyraldehyde. After one recrystallization fromacetone, a white solid melting at 246-269 C. was obtained.

By employing the procedure set forth in Example 3, the compounds listedin Examples 4-6 were prepared from two moles of S-acenaphthenol and onemole of the appropriate carbonyl compound. The crude reaction productsrepresented substantially quantitative yields of the desired4,4'alkylidenebis(5-acenaphthenols), and the products obtained directlyfrom the reaction mixture were evaluated as lard antioxidants withoutfurther purification. Since the longer alkyl chains attached to themethylene bridge increase the solubility of the bisacenaphthenols in thesolvents used in the reaction mixture, it was necessary to isolate theproduct both from the filter cake and filtrate to obtain optimum yields.The products were buff to light brown in color.

Example 7.-Preparaton of 4,4'secbutylidenebis (5-acenaphthenol) Aspreviously mentioned, ketones require more drastic ,conditions thanaldehydes in order to effect the desired condensation withS-acenaphthenol. The following cibernplifies such a reaction involvingketones:

A mixture of 8.5 g. (0.050 mole) of 5-acenaphthenol, 1.8 g. (0.025 mole)of methyl ethyl ketone, 60 ml. of benzene and 2 g. of pulverized zincchloride was satu rated with anhydrous hydrogen chloride. The mixturewas then refluxed for 1.5 hours and steam bath. After cooling, the solidproduct was filtered and washed well with water. The product wasrecrystallized twice from acetone-water mixtures to give 0.8 g. of awhite solid melting at 23S-240 C.

naphthenols) as lard antioxidants The4,4-alkylidenebis(S-acenaphthenols) such as have been described inExamples 1-7 were very elective in stabilizing lard against oxidationdeterioration. According to AOM test data, these compounds are superioras TABLE I AOM Values, Antiox. Antioxidant Added (0.02% Concentration)Hrs. to Index Reach PV 20 None (control lard No. L42) 16 BHA (2- and3isomers of tert. butyl-4-hydroxyanisole) 41 1. 0 BHT (3,5-ditert.butyl-t-hydroxytoluene) 52 1. 3 Propyl Gallate 2. 2 NDGA(nordihydroguaiaretic acid) 2. 4 2,2-Methylenebis (G-tert-butyLp-cresol)100 2. 4 4,4Methylenebis(-acennphthenol) 235 5. 7 4,4Ethylidenebis(5acenaphthenol) 210 5. 1 4,4Propylidenebis(-acenaphtheuol)220 5. 4 4,4Isobutylidenebis(-acenaphthenol) 250 6. 14,4'Butylidenebis(-acenaphthenol) 240 5. 9 ll,4(2ei:bylhexylidene)bis(5a conaphthenol) 190 4. 6 4,4-see-Butylidenebis(Sacenaphthcnol) 2155. 3

In Table I, lard was employed as the substrate being stabilized, and thestability was evaluated by the accelerated Active Oxygen Method (AOM)wherein air is bubbled through the lard containing the antioxidant at atemperature of 98.8 C. and the oxidation is followed by a determinationof the milliequivalents of peroxide formed per kilogram of substrate.Ordinarily, a peroxide value (PV) of 20 is the upper limit which can betolerated in edible fats. Above this value, the fats exhibit anobjectionable degree of rancidity. Thus in Table I, the number of hoursrequired to reach a peroxide value of 20 milliequivalents per kilogramare set out. The last column in the table headed antioxidant index showsthe comparative activity of the antioxidants based on the activity ofbutylated hydroxy anisole as 1.

As can be seen from Table I, the particular compounds of this inventionas listed are from 4.6 to 6.1 times as effective as BHA. It is apparentthat these compounds are from 1.9 to 2.5 times as effective as NDGA. Theisobutylidene derivative is the especially preferred antioxidant of thisinvention.

This application is somewhat related to a copending application filedAugust 10, 1954, by C. E. Tholstrup et al., Serial No. 449,016, whichdescribes other applications of antioxidants illustratingv still furtherhow the present invention can be practiced.

According to a preferred embodiment of this invention, there is providedfats and oils stabilized with at least 0.000l% by weight of a compoundhaving the following formula:

CH2-CH3 CH2-CH2 wherein R and R each represents a member selected fromthe group consisting of a hydrogen atom and an alkyl radical containingfrom l to 8 carbon atoms.

Generally, from about 0.001 to about 0.1% by weight of at least one ofthese antioxidants can be advantageously employed. Of course, higher andlower amounts, based on the weight of the substrate, can also be used.

Fats and oils in their broad sense include animal, vegetable, fish andmineral oils, waxes, fuels, lubricants, fats, greases and the like, e.g. lard, lard oil, cottonseed oil, peanut oil, lanolin, mutton tallowand grease, beef tallow, white and yellow greases, linseed oil, codliver oil, castor oil, olive oil, coconut oil, palm oil, corn oil,paraflin oil, carnauba wax, paraffin wax, beeswax, sperm oil, kerosene,gasoline, transformer oils, essential oils, citrus oils such as lemonoil, mono, diand triglycerides of various saturated and unsaturatedfatty acids, hydrogenated fats and oils, etc., as well as materialscontaining a substantial proportion of any of the waxes, fats or oils,e. g. fish meals, certain animal feeds, paint vehicles, furniturepolishes, floor waxes, automobile polishes, cottage cheese, milk, milksolids, powdered or whole eggs, egg yolks, mayonnaise, butter,margarine, salad dressing, etc. The term fats and fatty oils in the morelimited sense includes those materials containing esters derived fromglycerine, i. e., the various glycerides of the so-called fatty acids.

Similarly improved results are obtained by incorporating a4,4-alkylidenebis(5-acenaphthenol) in any of the other normallyoxidizable materials which require an antioxidant during use. Thus, bymeans of this invention, compositions of greatly improved stabilityagainst oxidation are readily obtained. The antioxidant effect of a4,4alkylidenebis(5acenaphthenol) makes the preparation of highly stablecompositions possible, and the antioxidant can be used in much lowerconcentrations than was possible with the antioxidants employedheretofore. As with other antioxidants, the4,4alkylidenebis(5-acenaphthenols) can be employed alone as shown in thedata set out in the table, or they can be employed in combination withother members of their group or with one or more other stabilizers suchas are well known in the art, including the phenolic stabilizers, aswell as the stabilizing acids such as citric acid, tartaric acid,ascorbic acid, and the like, as well as the esters of organic acids andother well known stabilizing materials.

The invention has been described -in considerable detail with particularreference to certain preferred embodiments thereof, but it will beunderstood that variations and modiiications can be employed within thespirit and scope of the invention as described hereinabove and asdelined in the appended claims.

We claim:

1. A new class of chemical compounds having the following formula:

wherein R and R' each represents a member selected from the groupconsisting of a hydrogen atom and an alkyl radical containing from 1 to8 carbon atoms.

. 4,4methylenebis( 5-acenaphthenol)4,4isobutylidenebis(S-acenaphthenol).

. 4,4ethylidenebis(5-acenaphthenol).

. 4,4'- 2-ethylhexylidene bis 5acenaphthenol)4,4-butylidenebis(S-acenaphthenol).

Fats and oils stabilized with at least 0.001% by weight of a compoundhaving the formula:

(IDH 0H wherein R and R' each represents a member selected from thegroup consisting of a hydrogen atom and an alkyl radical containing from1 to 8 carbon atoms.

8. Lard stabilized with at least 0.001% of 4,4'methyl enebisS-acenaphthenol) 9. Lard stabilized with from about 0.001% to about 0.1%by weight of 4,4methylenebis(5-acenaphthenol).

10. Lard stabilized with from about 0.01% to about 0.1% by weight of4,4isobutylidenebis(5-acenaphthenol).

11. Lard stabilized with from about 0.01% to about 0.1% by weight of4,4ethylidenebis(5acenaphthenol).

12. Lard stabilized with from about 0.01% to about 0.1% by weight of4,4propylidenebis(S-acenaphthenol).

13. Lard stabilized with from about 0.01% to about 0.1% by weight of4,4'butylidenebis(5-acenaphthenol).

14. A composition comprising a normally oxidizable organic materialstabilized with a compound of the formula wherein R and R' eachrepresents a member selected from the group consisting of a hydrogenatom and an alkyl radical containing from 1 to 8 carbon atoms.

No references cited.

1. A NEW CLASS OF CHEMICAL COMPOUNDS HAVING THE FOLLOWING FORMULA: